1. Field of the Invention
The present invention is concerned with protecting biological material from cell-damaging factors.
2. Description of the Related Art
It is known that the integrity of biological material, such as animal or human cells, tissues or organisms, can be damaged by a large number of a very wide variety of factors. These factors, can, for example, be energy-rich or ionizing radiation, such as radioactive radiation, X-radiation, cosmic radiation, etc., or ultraviolet light (UV light). While ionizing radiation is on the one hand one of the noxious environmental factors, on the other hand it can also be employed usefully in medicine. In this connection mention may be made of X-ray diagnostics, nuclear medicine and radiation therapy. This energy-rich radiation is characterized by the fact that it has the ability to ionize molecules.
Other important cell-damaging factors are chemical agents, for example, in the form of environmental poisons, but also such chemical agents which are used in the context of medical treatments as therapeutic agents, for example cytostatic agents. The latter are a chemically heterogeneous group of cytotoxic pharmacological substances which prevent, or delay substantially, the division of functionally active cells by affecting their metabolism in a variety of ways. Cytostatic agents are principally used in tumor therapy, with the starting-point for their activity being the fact that the rate at which tumor cells divide is higher than that of normal cells. Various groups of cytostatic agents are known: alkylating agents (e.g., cisplatin); antimetabolites (e.g., folic acid antagonists); mitosis inhibitors, antibiotics (e.g., bleomycin); enzymes (e.g., L-asparaginase); and others.
These factors can induce damage at all levels of biological organization, thus, reactions at the molecular or macromolecular (e.g., nucleic acid) level and at the cellular level, or tissue reactions or reactions involving the entire organism are seen in response to the influence of these factors.
Examples of damage which is induced by energy-rich radiation or ultraviolet radiation are an alteration of DNA, that is mutagenesis, which can lead to tumor development, and the degeneration, atrophy, fibrosing or necrosis of such tissues which are subjected to a high level of radiation.
Thus, the development of malignant melanoma, for example, is promoted by the skin being exposed extensively to the sun.
As was mentioned at the outset, the human organism is confronted with particularly high radiation intensities not only in connection with a high level of exposure to sunlight, but also during X-ray diagnosis, when there is an appropriate medical indication, or when radiation therapy is used in connection with tumor diseases. Radiologists, dentists, traumatologists, technical assistants in radiology, and workers in X-ray tube factories, are also particularly at risk in this connection.
The abovementioned cytostatic agents, which are to be categorized as being particularly important as far as causing cell damage is concerned, cause damages when used in the human body especially because the differences in division rate between normal and tumor cells are insufficient for selectively targeting tumors in a specific manner. The undesirable side effects or cytostatic agents therefore result, in particular, from a general inhibition of the regeneration of rapidly proliferating tissue. Blood cell formation, epithelia of the mucous membranes, whose inhibition of regeneration leads to gastrointestinal disturbances, and skin and skin appendages, whose inhibition of regeneration leads to hair loss, are particularly affected.